Regge approach to charged pion photoproduction at invariant energies above 2 GeV

Abstract

A Regge model with absorptive corrections is employed in a global analysis of the world data on positive and negative pion photoproduction for photon energies from 3 to 8 GeV. In this region resonance contributions are expected to be negligible so that the available experimental information on differential cross sections and single polarization observables at −t≤2 GeV 2 allows us to determine the non-resonant part of the reaction amplitude reliably. The model amplitude is then used to predict observables for photon energies below 3 GeV. Differences between our predictions and data in this energy region are systematically examined as possible signals for the presence of excited baryons. We find that the data available for the polarized photon asymmetry show promising resonance signatures at invariant energies around 2 GeV. With regard to differential cross sections the analysis of negative pion photoproduction data, obtained recently at JLab, indicates likewise the presence of resonance structures around 2 GeV. PACS. 11.55.Jy Regge formalism -13.60.Le Meson production -13.60.-r Photon and charged-lepton interactions with hadrons -25.20.Lj Photoproduction reactions

Proton-proton scattering above 3 GeV/c

“…Obviously, it is an open question down to which energies such a phenomenological Regge approach can provide a quantitative description of the available data. We find that the phenomenology allows to achieve a useful representation of the data down to 3 GeV/c, in line with analogous investigations for pion-nucleon scattering [33,34,35,36,37]. The Regge region therefore turns out to have a significant overlap with the kinematical region covered by the COSY-EDDA and SATURNE pp experiments.…”

P -wave excited baryons from pion- and photo-induced hyperon production

“…For kaon photoand electroproduction off protons, a gauge invariant chiral unitarity framework was developed in [166]. Also considered are Regge models [167,168,169,170] and heavy mesons [171]. The Gießen group [172,173,174,175,176,177,178,179,180,181] pioneered coupled-channel analyses of large data sets.…”

Photon inducedΛ(1520)production and the role of theK*exchange

“…This quark-gluon string picture was introduced by Kaidalov [14] and Donnachie and Landshoff [15] more than 20 years ago, and it has been used for photon and hadron induced reactions with energies above a few GeV [16]. Recently, the quark-gluon string model has been used extensively for the photoproduction of pions above 2 GeV [17].…”